(from Susan's Tip of the Month in the Monthly e-Mail Update)
Here's a simple idea with lots of ripple effects. If you have a large job to complete with volunteers, especially something that can be done in a group, make a party out of it. Photocopy some "invitations" that volunteers can give to their friend who are not volunteers, asking them to join in the activity at such and such date and time. For example:
"The pleasure of your company is wanted to participate in our Wrap-the-Toys or Sort-the-Clothes, or Weed-the-Garden party on ___________, from ___ to ___ p.m., in room 405 of Hometown Agency. As a friend of one of our wonderful volunteers, you are very welcome to join in this activity. You'll have fun, spend some time with your friend (and maybe make new ones), and do a good deed! Light refreshments provided. Dress: casual. RSVP through the volunteer you know."
You can even add a P.S. such as: "No strings attached. This is a one-time volunteer event."
The invitations can be focused on special target groups, too. You might want to hold an intergenerational party (volunteers invite someone at least 15 years older or younger than themselves) or a singles party (females bring a male and vice versa). However, the real "tip" here is to print these invitations! This gives volunteers the tool they need to broach the subject with their friends. Simply saying "please ask someone to join us" is not enough to make this a real success.
Obviously, such an approach can double your work force for the day. And, if you select the right work assignment, you don't have to worry about your usual screening and training process (among other thing, the "host" volunteer is a reference and will be accompanying the visitor). For a really big project, hold several "parties" by giving different dates on different invitations. The point is that every volunteer knows someone interested enough in what s/he does as a volunteer to pitch in to help one time. Be respectful of "no strings attached," but be sure everyone in attendance learns how to volunteer more if so desired!